One of the fundamental difficulties in understanding the neural basis of perception/cognition is, understanding the computational or informational significance of neural activity. This topic is of central importance to understanding brain function at all levels. The enormous complexity of the brain and the behavior it generates demands the development of sophisticated theories of neural coding and communication on a large scale. While this is a largely intractable problem, a variety of recent experimental and computational studies make this a timely topic for a symposium. We propose to hold a Symposium at the Center for Visual Science in June, 2000, on the topic of neural coding. This will be the 22nd in our Symposium series, beginning in 1964. The goal is to have speakers using a variety of approaches: optical imaging, in vitro slice preparations, anatomy, single and multi-cell recordings, and psychophysics, and to consider the information encoded in events at individual synapses, in single neurons, small scale circuits and the overall flow of information through the brain in a simple sensory-motor act. In the tradition of past CVS Symposia, the goal is to bring recent developments in this fundamentally important topic to a broader audience than that captured by more specialized meetings. We also wish to bring together speakers from a wider variety of areas than usual in order to promote interactions between groups of investigators from diverse areas. This, too, is in the tradition of CVS Symposia.